Multi-mode Superconducting Circuits for Building Programmable Multi-qubit Quantum Processors

Dr. Tanay Roy (host Murch), Tata Institute for Fundamental Research
February 28, 2018 at 11:00 am
241 Compton
Event Description 

Quantum processors are capable of providing enormous speedup to certain problems by exploiting classically inaccessible paths. A vast majority of the small-scale quantum processors demonstrated so far in solid-state systems rely on the nearest-neighbor coupling. The limited connectivity and native gates restricted between two qubits hinder efficient implementation of many quantum algorithms. In this talk, I will introduce the "trimon" [1], a longitudinally coupled three-qubit system based on a multi-mode superconducting circuit. I will first describe how we can achieve universal programmability by utilizing elementary controlled-controlled-rotations and all-to-all connectivity. Reconstruction of the density matrix for an arbitrary three-qubit state is accomplished using a joint readout scheme. I will then discuss the performance of the single-pulse generalized Toffoli gates and the preparation of different two- and three-qubit entangled states. Another unique feature of t his system is the ability to implement error-free CCZ gate [2] which simplifies the construction of various quantum oracles. I will demonstrate these capabilities by executing various quantum algorithms like Deutsch-Jozsa, Bernstein-Vazirani, Grover, quantum Fourier transform etc. on the three-qubit processor. Finally, I will discuss the possibility of building larger quantum processors using these longitudinally coupled multi-qubit systems.

Coffee: 10:45 pm, 241 Compton